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Title: Clock synchronization across standard networks
Author: Chuang, Y.-A.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1994
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In distributed real-time systems, data are time-dependent and the time notation, which marks the validity of data, is an indispensable component of data. Therefore, setting up a common time base in distributed real-time systems to provide all computers in the system with a consistent view of time inevitably becomes important. Clock synchronization is an approach to establishing such an greed global time base in a system. The aim of work is to investigate clock synchronization in a distributed real-time system. A hybrid synchronization method is adopted in the project. By this means, each computer in the system periodically exchanges time messages with other computers via the existing communication network, and thus knows the clock time of every other computer which participates in the clock synchronization. Then, it applies a synchronization algorithm on the received time data to compute an approximate global time for the system, and finally adjusts its local clock to the computed global time. An approximate global time is thus reached and maintained. In this dissertation, various approaches are studied and compared. A hybrid scheme is proved to be the currently dominant solution to the problem investigated, in that it balances the performance and cost criteria. The fault tolerant averaging algorithm selected for this attempt is discussed and analysed, and its software implementation is described. The design and silicon implementation of the associated VLSI clock synchronization unit device are also introduced. The experiments with clock synchronization on an Ethernet system are presented. The results of the experiments are given and analysed to support the conclusions that the technique developed in this work is feasible and can be used in distributed real-time systems. On this basis, recommendations for further research in clock synchronization are suggested.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available